Goodbye Cameron the Conciliator, hello Cameron the Destroyer. Empowered by last week's elections, the prime minister knows that he can get away with almost anything. Voters failed to punish him for attempting to dismantle the NHS and for ripping up his promise to protect frontline services. What can't he now do?

His next target is the environment. Within the following two weeks – probably on 16 May – the cabinet will decide whether or not to drop its commitment to prevent runaway climate change.

Illustration by Daniel Pudles

When the 2008 Climate Change Act was being debated, both the Conservatives and the Liberal Democrats called for it to be strengthened. David Cameron argued its targets for cutting carbon should be set not by politicians but by a group of experts, now called the Committee on Climate Change. In 2006 he insisted that this body should "set and enforce these targets, not merely monitor them as the government is proposing". The timetable for reducing greenhouse gases, he said, should be "free of political interference". The reason, he explained in another article, was to prevent governments from putting "short-term electoral considerations above the long-term interests of the country and the planet".

The act was passed but – to Cameron's professed disappointment – it allowed the government to overrule the five-yearly carbon budgets proposed by the committee. It did, however, set a legally binding overall target: an 80% cut by 2050. Governments could reduce their own commitments only by dumping them on their successors. The 80% target fell short of what the Liberal Democrat Chris Huhne, who is now secretary of state for energy and climate change, demanded. In an article for the Guardian in 2007, he announced that the Lib Dems "want no less than a zero-carbon Britain by 2050".

Now, as Friends of the Earth has discovered, the coalition could be about to rip up its commitments. The Treasury, the Department for Transport and the business department (run by the Lib Dem Vince Cable) have been lobbying within government to overturn the committee's advice that, to stay on target, carbon should be cut by 60% by 2030. So much for George Osborne's promise in 2009 that "under a Conservative government, the Treasury will no longer be the cuckoo in the Whitehall nest when it comes to climate change".

Other departments, including Huhne's, have been trying to defend the target. The decision has already been delayed several times: it now looks as if the showdown will take place at the meeting of the cabinet's economic affairs committee on Monday. If Osborne and Cable win, this will be the first time the climate targets have been rejected. It would set a disastrous precedent: the parties in power today will be unable to hold future governments to account if they too let the schedule slip.

Friends of the Earth argues that if the Treasury and the business department win, Huhne must resign. To stay on under those circumstances would be to lose all remaining credibility. The central purpose of his department, and of his career in government, is to enforce the act.

But this is just the beginning of the coalition's assault on the environment. The government's Red Tape Challenge presents, on paper at least, the widest-ranging threat to environmental protection since the enclosure acts. Suddenly it is asking whether environmental legislation – yes, all of it – should be "scrapped altogether". Listed as negotiable are the entire Climate Change Act, the clean air acts, the rules governing ozone-depleting chemicals, the Town and Country Planning Act, the Countryside and Rights of Way Act, the acts establishing national parks (and therefore the parks themselves), the rules enforcing energy efficiency, governing hazardous waste, preventing litter and dog-fouling: all the regulations, grand and petty, that protect us from other people's greed and selfishness.

It's a breathtaking, astonishing initiative, and the little protest it has generated testifies to how punchdrunk this country has become as the government pummels every protection our forebears worked so hard to win, everything that defends us from a feral, unregulated market.

The point of the Red Tape Challenge is not to scrap all this legislation but to shake the bolts looser. The government is in the process of resetting the political boundaries so that the outrageous propositions it makes in future seem unexceptional. The Tory frontbench is composed of very clever, calculating people. They know just what their sponsors in the corporate class expect of them, and just what they have to do to soften us up for the next assault.

They will not be unaware of the way the wind is blowing on the frontline of British environmental conflict. The regions in which big renewable power plants are due to be installed are in full-scale political revolt. The anger is directed not so much against the wind turbines as against the associated infrastructure. Here in Montgomeryshire, for instance, the turbines divide the community; the powerlines and substations unite it – in horror and revulsion. At the end of April 2,000 people (a remarkable number in this sparsely populated region) gathered to hear their Tory MP Glyn Davies denounce the current plans. Two weeks later the Tories won the Welsh assembly seat on a major swing. I've recently returned from the Scottish Highlands, where the upgrade to the Beauly-Denny powerline is provoking similar reactions.

Three conclusions seem obvious. Unless the new powerlines are buried, the renewables programme will stall: underground cables must become a firm green demand, though they will add significantly to the cost. Even so, it's now clear that there's a limit to how much more renewable power can be deployed before it clatters into a mountain of public opposition. This is one of the reasons why we should start considering other options for decarbonising the electricity supply: especially new nuclear technologies such as thorium, integral fast reactors or travelling wave reactors.

Until we in the environment movement decide how we're going to resolve these conflicts, the government needs only sit back and watch us tear ourselves apart, as scenery goes head-to-head with carbon. Cynical ministers know that there are few votes to be lost, and plenty to be gained, by abandoning these plans.

This is a perilous moment, at which greens could easily find themselves outmanouvred by a ruthless government. Cameron is the embodiment of a ruling culture detached from the fears and fortunes of those it dominates, that preaches responsibility but practises as little as it can get away with, that will uproot any tree that shelters us from the corporate gale. The "greenest government ever" presents the greatest ever threat to our environment. What are we going to do about it?